TWI567661B - Image capturing method and image capturing device - Google Patents

Description

Image capturing method and image capturing device

The present invention relates to an image capturing method, and more particularly to an image capturing method and an image capturing device for calculating and correcting captured images by obtaining a first displacement data and a second displacement data.

Due to the increasing reliance on handheld devices, such as smart phones or tablets, in modern society, the need for digital digitization has become stronger. Usually, a paper document is digitized by image capture such as scanning or photography to be converted into a digital file. Among them, portable image capturing devices, such as portable scanners, have become the mainstream in the market because of their advantages of being easy to carry and ready for use.

There are two main forms of common portable scanners. The first is to add a roller structure on the contact surface between the portable scanner and the paper to help the user to stably move the portable scanner. This method cannot avoid image distortion and skew caused by operation errors. Moreover, it is difficult to reduce the weight and volume of the hardware part, which causes inconvenience in carrying; the second is the mechanism of using automatic paper feeding, although this method can completely avoid the artificial operation error, but the weight of the configuration required in this way The volume is more than the first one, which greatly reduces the portability. At the same time, it must be limited by the size of the portable scanner, and the function of scanning books or large targets is lost.

Therefore, how to develop a different image acquisition method and adopt a hardware architecture different from the traditional configuration to improve the problems and shortcomings in the prior art, thereby enhancing the user experience, is indeed important in the current technical field. Question.

The main purpose of the present invention is to provide an image capturing method and an image capturing device, which solve and improve the problems and disadvantages of the foregoing prior art.

Another object of the present invention is to provide an image capturing method and an image capturing device, which are capable of diversifying the first displacement data and the second displacement data by acquiring the captured image, the first displacement data, and the second displacement data. The calculation can output the captured image as the corrected terminal image. Not only makes the captured image close to the original image, but also greatly improves the image quality, and the image capture can be performed freely without being restricted to any operation mode, thereby effectively improving the user experience.

Another object of the present invention is to provide an image capturing method and an image capturing device, which can perform image correction by calculating the first displacement data and the second displacement data, so that the image capturing device only needs to be configured in a small and lightweight manner. The first optical displacement sensor and the second optical displacement sensor do not need to use a mechanical component to stabilize the image capturing process in a conventional manner, so as to achieve a product that greatly reduces the volume of the product and effectively reduces the total weight of the product.

In order to achieve the above object, a preferred embodiment of the present invention provides an image capturing method, including the steps of: (a) providing an image capturing device; and (b) obtaining at least one captured image and at least one first displacement data. And at least one second displacement data; (c) calculating an angular deflection data according to the first displacement data and the second displacement data; (d) according to the first displacement data, the second displacement data, and the angular deflection data Calculating a true coordinate of a center point corresponding to a center point of the image capturing device; (e) calculating one of the starting points of the captured image according to the angle deflection data and the true coordinate of the center point a true coordinate of the starting point and an ending point corresponding to an end point; and (f) determining a true coordinate system based on the true coordinate of the center point, the true coordinate of the starting point, and the true coordinate of the ending point, and determining the true coordinate system The image is taken to correspond to the real coordinate system output to obtain a corrected terminal image.

In order to achieve the above object, another preferred embodiment of the present invention provides an image capturing device, including: a control unit; a first optical displacement sensor coupled to the control unit for obtaining a first Displacement data; a second optical displacement sensor coupled to the control unit for obtaining a second displacement data; and a contact image sensor coupled to the control unit for obtaining a capture The image control unit determines a real coordinate system based on the first displacement data and the second displacement data, and outputs the corrected image to the real coordinate system to obtain a corrected terminal image.

1‧‧‧Image capture device

10‧‧‧Control unit

11‧‧‧First optical displacement sensor

12‧‧‧Second optical displacement sensor

13‧‧‧Contact Image Sensor

100‧‧‧ body

D‧‧‧Distance

P1, P2, P1', P2'‧‧‧ position

S100~S600‧‧‧Steps

S100~S800‧‧‧Steps

Figure 1 is a flow chart showing an image capturing method of the preferred embodiment of the present invention.

Figure 2 is a flow chart showing an image capturing method in another preferred embodiment of the present invention.

Figure 3 is a block diagram showing the architecture of the image capturing device of the preferred embodiment of the present invention.

Figure 4 is a bottom plan view of the image capture device of the preferred embodiment of the present invention.

Figure 5 is a schematic diagram showing the original displacement data and the displacement data by angular deflection.

Figure 6 is a schematic diagram showing the relative position and the deflection angle of the image capturing device before and after the movement based on the first displacement data and the second displacement data.

Figure 7 is a schematic diagram showing the original coordinate system and the real coordinates of the image capturing method of the present invention.

Some exemplary embodiments embodying the features and advantages of the present invention are described in detail in the following description. It is to be understood that the present invention is capable of various modifications in various aspects, and is not to be construed as a limitation.

Please refer to FIG. 1 to FIG. 4 , wherein FIG. 1 is a flow chart showing an image capturing method according to a preferred embodiment of the present invention, and FIG. 2 is a flow chart showing an image capturing method according to another preferred embodiment of the present invention. 3 is a block diagram showing the structure of the image capturing device of the preferred embodiment of the present invention, and FIG. 4 is a bottom view showing the image capturing device of the preferred embodiment of the present invention. As shown in FIG. 1 to FIG. 4, the image capturing method of the present invention includes at least steps S100 to S600. The process step of the image capturing method starts in step S100, and the image capturing device 1 is provided. The image capturing device 1 includes a body 100, a control unit 10, a first optical displacement sensor (ONS) 11, a second optical displacement sensor 12, and a contact image sensor (CIS). )13. The control unit 10, the first optical displacement sensor 11, the second optical displacement sensor 12, and the contact image sensor 13 are preferably disposed on the body 100. The control unit 10 is configured to control the overall operation of the image capturing device 1 , and the first optical displacement sensor 11 , the second optical displacement sensor 12 and the contact image sensor 13 are connected to the control unit 10 .

Next, as shown in step S200, at least one captured image, at least one first displacement data, and at least one second displacement data are obtained. The captured image is obtained by the contact image sensor 13 , the first displacement data is acquired by the first optical displacement sensor 11 , and the second displacement data is acquired by the second optical displacement sensor 12 , but Not limited to this.

In the case where the contact image sensor 13 and the first optical displacement sensor 11 and the second optical displacement sensor 12 respectively acquire the captured image, the first displacement data, and the second displacement data, The contact image sensor 13 and the first optical displacement sensor 11 and the second optical displacement sensor 12 are interlocked with each other, which inevitably causes the shortest time of each column of the image capture, which is the most The speed of fast tolerance is reduced, which affects the convenience of use. Therefore, in the preferred embodiment of the present invention, The contact image sensor 13 is not linked with the first optical displacement sensor 11 and the second optical displacement sensor 12 to enhance the user's operating experience. Specifically, in step S200, the contact image sensor 13 of the image capturing device 1 acquires a captured image at every other distance, and the first optical displacement sensor 11 of the image capturing device 1 and the first The two optical displacement sensors 12 acquire a first displacement data and a second displacement data at intervals of time. Thereby, the contact image sensor 13 can be operated at full speed, and the first displacement data and the second displacement data obtained by the first optical displacement sensor 11 and the second optical displacement sensor 12 are interpolated to calculate the contact type. The image sensor 13 captures the information of each column of the image.

Next, as shown in step S300, an angular deflection data is calculated based on the first displacement data and the second displacement data. Please also refer to Figures 1 to 5, where Figure 5 shows the original displacement data and the displacement data of the angular deflection. Generally, the first displacement data and the second displacement data obtained by the image capturing method of the present invention include two vectors U and V perpendicular to each other, and the first optical displacement sensor 11 and the second optical displacement sense. When the sensing of the detector 12 is different from the previous measurement by a deflection angle θ, the measured first angular displacement of the angular deflection and the two vectors U', V' included in the second displacement data are also original The two vectors U and V included in the first displacement data and the second displacement data are different from the deflection angle θ . In order to correct the deviation, the calculation of the deflection angle θ is necessary.

To calculate the deflection angle θ and further obtain the angular difference, the vector relationship and the distance D between the first optical displacement sensor 11 and the second optical displacement sensor 12 are used for calculation. Please refer to FIG. 6 , which is a schematic diagram showing the relative position and the deflection angle of the image capturing device before and after the movement according to the first displacement data and the second displacement data. As shown in FIG. 6, the position P1 and the position P2 represent the positions of the first optical displacement sensor 11 and the second optical displacement sensor 12 before the movement, and the position P1' and the position P2' represent the first optical. The position of the displacement sensor 11 and the second optical displacement sensor 12 after the movement is the distance between the first optical displacement sensor 11 and the second optical displacement sensor 12. Therefore, as can be seen from Fig. 6, the deflection angle θ can be calculated using an inverse sine function, that is, θ = sin ^-1 ((v ₁ - v ₂ ) / D). In addition, the angular difference θ _i between the i-th displacement data and the first displacement data may be Calculated.

Then, as shown in step S400, the center point real coordinate corresponding to one center point of the image capturing device 1 is calculated according to the first displacement data, the second displacement data, and the angle deflection data. In some embodiments, a center position of the contact image sensor 13 is overlapped with a center point of the image capturing device 1. In other words, the center point real coordinate obtained in step S400 can correspond to the center point of the image capturing device 1 and the center position of the contact image sensor 13 of the image capturing device 1 . In this step S400, if the current position of the first optical displacement sensor 11 is P1 and the current position of the second optical displacement sensor 12 is P2, the center point position Pc can be Pc=(P1+P2)/2. Calculated. If the first displacement data obtained by the first optical displacement sensor 11 after displacement is V1, and the second displacement data obtained by the second optical displacement sensor 12 after displacement is V2, the first optical displacement sensor 11 The position P1' after the displacement can be calculated by P1'=P1+V1, and the position P2' after the displacement of the second optical displacement sensor 12 can be calculated by P2'=P2+V2, and the center point position Pc' after the displacement can be obtained by Pc'=(P1'+P2')/2 is calculated.

Then, as shown in step S500, the real coordinates of the starting point and the ending point corresponding to the starting point corresponding to the starting point of the captured image are calculated according to the angle deflection data and the true coordinate of the center point. In this step S500, the real coordinate of the starting point and the true coordinate of the ending point are calculated through a linear interpolation and matrix conversion algorithm, but not limited thereto. In the foregoing steps S300 to S400, the center point Pc _i and the angle deflection θ _i when the i-th first optical displacement sensor 11 and the second optical displacement sensor 12 acquire the data have been calculated. If t(i) represents the time point of the ith reading of the first optical displacement sensor 11 and the second optical displacement sensor 12, t(j) represents that the contact image sensor 13 reads the jth column. At the time point, the manner in which the image center point Ic _j and the angle deflection Iθ _j of the jth column are interpolated is as follows:

Next, the formula for calculating the starting point coordinate Ia _j and the ending point coordinate Ib _j using the center point Ic _j and the angle deflection Iθ _j is:

Where L is the length of the CIS, , , .

Next, as shown in step S600, the real coordinate system is determined according to the true coordinates of the center point, the true coordinates of the starting point, and the real coordinates of the ending point, and the captured image is output corresponding to the real coordinate system to obtain the corrected terminal image. In this step S600, the algorithm of the triangle proportional relationship is used to determine the true coordinate system according to the true coordinates of the center point, the true coordinates of the starting point, and the true coordinates of the ending point. Please refer to Fig. 1 to Fig. 7, wherein Fig. 7 is a schematic diagram showing the original coordinate system and the real coordinates of the image capturing method of the present invention. As shown in Figures 1 to 7, in the point where the true coordinate is (x, y), the point (x', y') of the original image should be referred to. The calculation includes: first, find i, j, k The values are such that Ya _i = Yb _j = Yc _k = y , i, j is the range of y'; secondly, y' is obtained by the ratio of x, where:

After getting y', find x' again, where:

However, x's calculation of each point is too resource-intensive, so if θ _{y ' is} not large, change x ' = x - Xa _y' to speed up the processing. By using the above method, the image of the real coordinate can be re-outputted, that is, the corrected terminal image is obtained.

In some embodiments, step S300, step S400, step S500, and step S600 are preferably implemented by the control unit 10 of the image capturing device 1, but are not limited thereto.

In a variant embodiment, the image capturing method of the present invention further includes a step S700 after step S600 to determine whether image capturing is completed. If the result of the determination in step S700 is YES, step S700 is followed by step S800 to complete image capture; when the determination result of step S700 is no, step S200 to step S700 are performed again after step S700. In short, if it is determined that the image capture is still not completed, the above steps S200 to S600 are performed again to perform image capture and image correction, and it is determined again whether image capture is completed; and when it is determined that the image capture is completed In the case of performing image capture step S800, the flow of the image capture method of the present invention is terminated in step S800.

In summary, the present invention provides an image capture method for obtaining a captured image, a first displacement data, and a second displacement data, and performing diversified calculations on the first displacement data and the second displacement data. Take the image output as the corrected terminal image. Not only makes the captured image close to the original image, but also greatly improves the image quality, and the image capture can be performed freely without being restricted to any operation mode, thereby effectively improving the user experience. At the same time, since the image capturing method of the present invention can perform image correction by calculating the first displacement data and the second displacement data, the image capturing device only needs to be configured with a small and lightweight first optical displacement sensor and The second optical displacement sensor does not need to use a mechanical component to stabilize the image capturing process in a conventional manner, so as to achieve a function of greatly reducing the volume of the product and effectively reducing the total weight of the product.

The present invention has been described in detail by the above-described embodiments, and may be modified by those skilled in the art, without departing from the scope of the appended claims.

S100~S600‧‧‧Steps

Claims (10)

An image capturing method includes the steps of: (a) providing an image capturing device; (b) obtaining at least one captured image, at least one first displacement data, and at least one second displacement data; (c) according to the first The displacement data and the second displacement data are calculated to obtain an angle deflection data; (d) calculating, according to the first displacement data, the second displacement data and the angle deflection data, a center corresponding to a center point of the image capturing device Pointing the true coordinate; (e) calculating, according to the angle deflection data and the true coordinates of the center point, a starting point true coordinate of one of the starting points of the captured image and an ending point true coordinate corresponding to an ending point; and (f According to the true coordinate of the center point, the real coordinate of the starting point and the true coordinate of the ending point, a real coordinate system is determined, and the captured image is output corresponding to the real coordinate system to obtain a corrected terminal image. The image capturing method of claim 1, wherein the step (f) further comprises the step of: (g) determining whether image capturing is completed, wherein when the determining result of the step (g) is yes, After the step (g), the step is performed: (h) completing the image capture, and when the judgment result of the step (g) is no, after the step (g), the step (b) to the step is re-executed ( g). The image capturing method of claim 1, wherein the image capturing device comprises: a control unit; a first optical displacement sensor coupled to the control unit for obtaining the first displacement Data; a second optical displacement sensor coupled to the control unit for obtaining the second displacement data; A contact image sensor is coupled to the control unit for acquiring the captured image. The image capturing method of claim 3, wherein the step (c), the step (d), the step (e), and the step (f) are implemented by the control unit. The image capturing method of claim 3, wherein a center position of the contact image sensor is overlapped with the center point of the image capturing device. The image capturing method of claim 1, wherein in the step (b), the image capturing device acquires one captured image at every other distance, and obtains the image every other time interval. First displacement data and one second displacement data. The image capturing method of claim 1, wherein the step (c) further comprises the substep: (c1) calculating, by the inverse sine function, a deflection angle and an angular difference of the angular deflection data. The image capturing method according to claim 1, wherein in the step (e), the starting point true coordinate and the ending point true coordinate are calculated by a linear interpolation and matrix conversion algorithm. The image capturing method of claim 1, wherein in the step (f), the algorithm of the triangular proportional relationship is based on the true coordinate of the center point, the true coordinate of the starting point, and the ending point. The true coordinates determine the true coordinate system. An image capturing device includes: a control unit; a first optical displacement sensor coupled to the control unit for acquiring a first displacement data; a second optical displacement sensor, and the control unit Connected to obtain a second displacement data; and a contact image sensor connected to the control unit for obtaining a captured image; The control unit calculates an angle deflection data according to the first displacement data and the second displacement data, and calculates the image capturing device according to the first displacement data, the second displacement data, and the angle deflection data. A center point corresponds to a true coordinate of a center point, and according to the angle deflection data and the true coordinates of the center point, one of the starting points of the captured image corresponds to a starting point true coordinate and an ending point corresponds to one end point true coordinate And determining a real coordinate system according to the true coordinates of the center point, the true coordinates of the starting point, and the true coordinates of the ending point, and the captured image is corresponding to the real coordinate system output, and the corrected terminal image is obtained.